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He said it: Origin of life pioneer Leslie Orgel on challenge of OOL research

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Some sources treat the origin of life as if we had any idea how it really happened. But that is most certainly not the case. One key topic of The Design of Life is origin of life (OOL) – specifically the reasons why it is so difficult to figure out (Chapter 8).

In the context, it is worth remembering that recently deceased OOL pioneer Leslie Orgel of the Salk Institute for Biological studies (the “father” of RNA world – the idea that RNA molecules came first), had actually made the difficulties clear. For example, he said,

There is no agreement on the extent to which metabolism could develop independently of a genetic material. In my opinion, there is no basis in known chemistry for the belief that long sequences of reactions can organize spontaneously – and every reason to believe they cannot The problem of achieving sufficient specificity, whether in aqueous solution or on the surface of a mineral, is so severe that the chance of closing a cycle of reactions as complex as the reverse citric acid cycle, for example, is negligible.

(The Language of the Genes, Revised Edition, London, harper Collins, 2000, p. 35, quoted in John C. Lennox, God’s Undertaker: Has Science Buried God (London: Lion 2007), pp. 134–35)

Even Orgel’s New York Times obit sort of hints around the problem:

Writing in the journal Nature in 2006, Dr. Orgel reflected on his quest to comprehend the 4.5 billion years of life on Earth, a history that he described as “chaotic intellectual territory.”

Beyond the rudimentary timeline, he said, “almost everything else about the origin of life remains obscure.”

He added that only further and more penetrating research could reveal “the detailed steps that led from unconstrained abiotic chemistry to the organized complexity of biochemistry.”

This is good to keep in mind when we hear people puffing “RNA world” as though it offered some kind of easy solution to the origin of life. Note: Here are some other sources on why origin of life is such a difficult problem.

What if some initial information was essential to get life started? In that case, the reason current research projects have gone nowhere is that the researchers are not permitted to entertain as a possibility an element that is required as a fact. Rather they are forced to try to answer the question in terms of: How could it have been done with no previous information or intelligence at all?

If that is the only question they are permitted to ask, and if intelligence was indeed required, well then they will never find an answer. Or they will pretend to find an answer and demand that everyone believe it – or else.

Re the "chirality problem": Chirality In Life, The Earliest Surviving Darwinian Evolution Product http://www.physforum.com/index.php?showtopic=14988&st=180&#entry327715 A. From "...key to life before its origin on Earth?" http://www.physorg.com/news123440279.html#tab When scientists synthesize these molecules in the laboratory, half of a sample turns out to be “left-handed” and the other half “right-handed.” But the amino acids that are the building blocks of terrestrial proteins are all “left-handed,” while the sugars of DNA and RNA are “right-handed.” The mystery as to why this is the case, “parallels in many of its queries those that surround the origin of life...” Thanks to the pristine nature of this meteorite, we were able to demonstrate that other extraterrestrial amino acids carry the left-handed excesses in meteorites and, above all, that these excesses appear to signify that their precursor molecules, the aldehydes, also carried such excesses,” Pizzarello said. “In other words, a molecular trait that defines life seems to have broader distribution as well as a long cosmic lineage.” B. From "Allosteric, chiral-selective drug binding to DNA" http://www.pnas.org/cgi/reprint/97/22/12032.pdf (Allosteric: of, relating to, undergoing, or being a change in the shape and activity of a protein, as an enzyme, that results from combination with another substance at a point other than the chemically active site) DNA is polymorphic and exists in a variety of distinct conformations. Duplex DNA can adopt a variety of sequence-dependent secondary structures that range from the canonical right-handed B form through the left-handed Z conformation. Multistranded triplex and tetraplex structures are now known to exist. All of these unique conformations may play important functional roles in gene expression. C. Chirality in life still awaits elucidation First, reasearch findings should be stated scientifically correctly. In A above NOT "a molecular trait that defines life seems to have broader distribution as well as a long cosmic lineage”, but YES "a molecular conformation dominant in Earth life may have broader distribution and additional cosmic presence.” Next, re in A above "the mystery as to why this is the case": My conjecture about the probable reasons for the prevailing chirality: Darwinian evolution started at life's day one, with the genesis of the first organisms, the replicating oligomers, pre-archaea genes. It started under yet-unknown energetic conditions, by a serendipitous occurrence, with oligomeric (RNA?) conformations, in a soup containing all their essential molecular progenitors. These conformations happened to absorb the amounts of energy enabling their polymerization, to lengths precipitated as determined by the nature and conditions of the soup. The sugars and the nitrogen-based compounds that, together with the phosphates, are the components of the genes-organisms, are chiral. There probably is an energetic advantage in homochirality and chiral homogeneity for the self-replication of biopolymers. This serendipitous occurrence set up a matrix-field of energy with a potential extended between its source, the sun radiation and the precipitating organisms. This was the genesis of the ongoing formation and maintenance of Earth's biosphere. And since the biosphere had thus started it could only evolve in the directions of more favorable energy balances-life-packages and towards stabler conformations. Survival was the direction. After all, this was already the course of Earth life evolution. But this is a conjecture. Chirality in life still awaits elucidation... Dov Henis http://blog.360.yahoo.com/blog-P81pQcU1dLBbHgtjQjxG_Q--?cq=1 Dov Henis
I'm glad that the vent scenario is not being ignored by the critics of abiogenesis, because this is one argument that is far from settled. One side believes in abiogenesis, the other side believes in its impossibility, but neither has yet to come up with conclusive proof. I'm a fan of Hoyle-Wickramasinghe panspermia, in a non-expanding,non-BigBang Universe (see Halton Arp) that is far older than our 14 billion year old Galaxy. If there is only one kind of life in the Universe, namely ours, then abiogenesis is disproven. Finding common bacteria in an interstellar comet will be a big step in that direction. NeoDualist
Hi again Neo-D: Actually, the chirality issue is one of many generally fatal results for all sorts of chance + necessity only abiogenesis OOL models. (If you need a mountain each of the many components of a viable life system, then to get the right elements together in close proximity [~ 10^-6 m] rapidly becomes a beyond astronomical improbability.) Second, this is only one of a cluster of heavy challenges faced by RNA-first type models. Shapiro in Sci Am [cited in Section A of the same always linked], recently acidly remarked:
The RNA nucleotides are familiar to chemists because of their abundance in life and their resulting commercial availability. In a form of molecular vitalism, some scientists have presumed that nature has an innate tendency to produce life's building blocks preferentially, rather than the hordes of other molecules that can also be derived from the rules of organic chemistry . . . . A careful examination of the results of the analysis of several meteorites led the scientists who conducted the work to a different conclusion: inanimate nature has a bias toward the formation of molecules made of fewer rather than greater numbers of carbon atoms [NB: as statistical thermodynamics would tell you -- more ways to arrange configurations . . . so more microstates thence a higher statistical weight of the resulting small molecule macrostate], and thus shows no partiality in favor of creating the building blocks of our kind of life. (When larger carbon-containing molecules are produced, they tend to be insoluble, hydrogen-poor substances that organic chemists call tars.) I have observed a similar pattern in the results of many spark discharge experiments . . . . no nucleotides of any kind have been reported as products of spark discharge experiments or in studies of meteorites, nor have the smaller units (nucleosides) that contain a sugar and base but lack the phosphate. To rescue the RNA-first concept from this otherwise lethal defect, its advocates have created a discipline called prebiotic synthesis. They have attempted to show that RNA and its components can be prepared in their laboratories in a sequence of carefully controlled reactions, normally carried out in water at temperatures observed on Earth . . . . Unfortunately, neither chemists nor laboratories were present on the early Earth to produce RNA . . . .
He then goes on to a colourful discussion of the underlying probabilistic challenge:
The analogy that comes to mind is that of a golfer, who having played a golf ball through an 18-hole course, then assumed that the ball could also play itself around the course in his absence. He had demonstrated the possibility of the event; it was only necessary to presume that some combination of natural forces (earthquakes, winds, tornadoes and floods, for example) could produce the same result, given enough time. No physical law need be broken for spontaneous RNA formation to happen, but the chances against it are so immense, that the suggestion implies that the non-living world had an innate desire to generate RNA.
Of course, one point of my own discussion is that Shapiro's favoured metabolism first scenario also faces the same hurdle, tied to statistical thermodynamics issues. And, the chirality problem is common to both. As I recall, there is also a nucleic acid synthesis under plausible pre-life conditions problem. And so on. GEM of TKI kairosfocus
NeoDualist, Dr. Hugh Ross pointed out this objection, which also looks fa^tal to the hydrothermal vent scenario: http://www.reasons.org/resources/connections/2002v4n2/index.shtml Of special note: For the synthesis of prebiotic molecules at deep-sea hydrothermal vents (and for life to originate in this environment), ammonia (NH3) must be present. Ammonia serves as a key starting material in the synthesis of amino acids and other biologically important nitrogen-containing compounds. Researchers now recognize that ammonia did not exist on the early Earth. Therefore, high-temperature origin-of-life scenarios must be discarded unless ammonia somehow formed at deep-sea hydrothermal vents as a precursor to prebiotic molecules. Penn State and SUNY-Stony Brook researchers recently evaluated the likelihood of ammonia formation under primitive hydrothermal vent conditions.4 In principle, ammonia (NH3) could form in such an environment from nitrogen (N2) gas via two possible chemical routes involving hydrogen sulfide (H2S) and iron (2) sulfide FeS. Laboratory experiments conducted by the two researchers demonstrate that FeS-mediated reaction occurs far too slowly to have contributed to ammonia formation. Ammonia production by hydrogen sulfide occurs rapidly enough but yields insufficient quantities to sustain prebiotic molecule formation. This lack of adequate ammonia production makes the origin of life at deep-sea hydrothermal vents unlikely. Moreover, it eliminates another possible source of prebiotic molecules on the early Earth. Each new discovery makes the origin-of-life problem more intractable for naturalists. #4 Martin A. A. Schoonen and Yong Xu, “Nitrogen Reduction Under Hydrothermal Vent Conditions: Implications for the Prebiotic Synthesis of C-H-O-N Compounds,” Astrobiology 1 (2001): 133-42. bornagain77
Thank you for the link. I'm glad somebody is critiquing the RM model, but your homochirality objection is a mere detail compared to the fatal objections previous models had, since a strong magnetic field will take supply it. At least the Russell-Martin model gets to the very beginning of the RNA world, which is more than previous ones ever did. It also postulates two origin events, an original idea. As for the sedimentary rocks you mentioned, they require land, which is also a separate issue from underwater vents on a mostly ocean world. Also, said rocks were formed 500 million years after the two putative origin events. The level of detail in the RM model and the number of issues it successfully addresses go far beyond anything before it. Keep looking for more objections. NeoDualist
Hi Neo-D: Take a look at the discussion in my always linked through my name in the LH column, in Section B. You will find there, inter alia, my discussion of Section 6 of their 2001 paper, "On the origins of cells: a hypothesis for the evolutionary transitions from abiotic geochemistry to chemoautotrophic prokaryotes, and from prokaryotes to nucleated cells." Take a look (including my comment on their mass calculations to exhaustively search the configuration space to get to homochirality), then come back on the topic. [Sections A and C are also relevant.] You may find the following fromt hat section of interest:
none of the [current abiogenesis] models have proposed a solution to one of the more vexing origin problems: chirality. Three-dimensional molecules such as sugars and amino acids can exist in two mirror-image forms, like left and right hands (chiros is Greek for hand). Any nonbiological synthesis of such molecules, as would have occurred before life arose, produces equal amounts of each type. Nonetheless, modern cells use exclusively left-handed amino acids and right-handed ribose sugars, and interference from the wrong kind shuts down biological reactions. How could chiral life arise in the presence of so much interference? It's a serious problem, Orgel admits, but not an overwhelmingly serious one. Orgel suggests that one of several possible solutions may be chance, a frozen accident that brought together, and kept together, molecules of the right chirality. Such an accident is perhaps not so unlikely, says Martin, who calculates that a mixture of every possible left- and right-handed combination of a 25 amino acid peptide (amino acid chain) would weigh 25 kilograms [cf my calculation: more like ~2.5*10^13 tonnes, using 100 AMU as a reasonable estimate for amino acid molecular mass, and for 39 versions [Glycine being achiral] of the relevant amino acids of life, 39^25 ~ 5.99*10^39 possible molecules, ~ 9.94*10^15 moles]. Any smaller sample is imperfect, he says. [Emphases and sq braces added.]
So, as Denyse observed, Orgel has aptly remarked:
In my opinion, there is no basis in known chemistry for the belief that long sequences of reactions can organize spontaneously - and every reason to believe they cannot The problem of achieving sufficient specificity, whether in aqueous solution or on the surface of a mineral, is so severe that the chance of closing a cycle of reactions as complex as the reverse citric acid cycle, for example, is negligible.
Without those long sequences, you don't get to life functionality. And, without for instance homochirality, you don't get to the required geometry. GEM of TKI kairosfocus
NeoDualist, One major problem with this hydrothermal vent scenario, is that it still requires time to overcome probabilistic hurdles plus it requires to be underwater. The oldest sedimentary rocks on earth, known to science, originated underwater (and thus in relatively cool environs) 3.86 billion years ago. Those sediments, which are exposed at Isua in southwestern Greenland, also contain the earliest chemical evidence (fingerprint) of “photosynthetic” life [Nov. 7, 1996, Nature]. This evidence has been fought by naturalists, since it is totally contrary to their evolutionary theory. Yet, Danish scientists were able to bring forth another line of geological evidence to substantiate the primary line of geological evidence for photo-synthetic life in the earth’s earliest known sedimentary rocks (Indications of Oxygenic Photosynthesis,” Earth and Planetary Science Letters 6907 (2003). Thus we have two lines of hard conclusive evidence for photo-synthetic life in the oldest known sedimentary rocks ever found by scientists on earth! The simplest photosynthetic bacterial life on earth is exceedingly complex, too complex to happen by . bornagain77
You need to look at the articles yourself http://www.gla.ac.uk/projects/originoflife/html/2001/pdf_articles.htm http://www.molevol.de/publications/135.pdf http://www.molevol.de/publications/150.pdf http://www.nordita.dk/conference/AstroBioSchool/material/Russell/Russell+Martin04.pdf NeoDualist
NeoDualist- Does that paper demonstrate that they have created nucleotides in the lab, underwater and within rocks bodering a heat source? Joseph
O'Leary says: "If that is the only question they are permitted to ask, and if intelligence was indeed required, well then they will never find an answer." Permitted to ask? Hello? We can ask any question that we wish to ask. However, to ask a scientific question requires that we formulate it in such a way that the answer does not presuppose any condition that we cannot disconfirm. If we pose a requirement for intelligence as a precondition for life, then we must also pose a disconfirmable explanation for the origin of the intelligence. Without that, we don't have a working theory. But ID resists doing exactly that. That's the rock you seem to be stumbling on here. MacT
I am new here, but until recently I was unimpressed with abiogenesis, until I ran across the little-heralded Russell-Martin model, now ten years in print. Micropores in the 'Goldilocks' temperature zone within rocks bordering hot submarine vents produce the requisite RNA. Viz. their detailed paper in TRENDS in Biochemical Sciences, V29#7. Anyone wanting to deny the possibility of abiogenesis must confront this theory, and I'm not a biochemist (yet). Any takers? NeoDualist
Solon, "You might just say that we know there are no graspable answers to these questions outside of the guidance of the Word." Solon, it seems that you don't currently have the heart of an IDer. The creationist movement is quite happy to bring out the Bible and quote the Bible to declare scientific truth. The ID community is not so inclined. We would rather study scientific evidence without trying to fit it into any particular theological framework. It is this reality, in fact, that makes Judge Jones' decision such a joke. It is this reality that makes ID fundimentally not "religous". Please feel free to leave Biblical authority out if the scientific hypothesis of Intelligent Design. bFast
As far as a RNA-world is concerned, we already have one: retroviruses! A retrovirus begins with RNA, uses a reverse transcriptase to from a DNA provirus, and then inserts itself into an already existing cellular system. Thus retroviruses represent a RNA-world that is able to "replicate", and, at a fantastically high rate of replication and duplication, produces "very little", as says Michael Behe in EoE, speaking of the retrovrius HIV. So much for that thesis..... PaV
There you go O'Leary, quote mining!!!!! And evolution has nothing to do with the Origin of Life!!!!! Except when it does!!!! But that's only sometimes!!!! When nobody is looking!!! tribune7
The alleged "RNA World" has at least one main obstacle- that of nucleotides. RNA requires nucleotides but nucleotides only appear in living organisms. Joseph
Since it is obvious that a Creator is logically necessary, I don't see the point in trying to debate with darwinists over these insignificant details to their imaginary hypotheses by arguing about the questions they are allowed to ask. You might just say that we know there are no graspable answers to these questions outside of the guidance of the Word. Attempts to do 'science' in the arena of origins of anything is a fool's errand and we must not fall into that trap, instead let us stand by the Truth which is God said Let There Be And It Was Good. Solon

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